TWI418277B - Method for producing a circuit board - Google Patents

Description

Circuit board manufacturing method

The present invention relates to a method of manufacturing a circuit board.

In recent years, as a means of forming an electronic circuit, a circuit pattern is widely used on a plastic substrate, a ceramic substrate, or an insulating substrate coated with plastic, and a solder-bonded IC device, a semiconductor wafer, a resistor, a capacitor, etc. are mounted thereon. The method of electronic parts.

Wherein, the method of bonding the wire terminal of the electronic component to a specific portion of the circuit pattern is generally performed in the following steps: a step of forming a solder thin layer on the surface of the conductive circuit electrode on the substrate; printing on the solder thin layer a step of solder paste or flux; a step of positioning a specific electronic component; and a step of soldering or solidifying the solder thin layer or the solder thin layer and the solder paste.

Further, recently, with the miniaturization of electronic products or circuit boards, the fine pitch of electronic components has been demanded. As for these electronic parts, for example, a QFP (Quad Flat Package) of 0.3 mm pitch, a CSP (Chip Size Package), a Flip Chip (Flip Chip) of 0.15 mm pitch, and a BGA structure are known. LSI wafers, etc. Further, a method of mounting an electronic component on a circuit board is known in which a solder bump formed on an electronic component is overlapped with a solder bump formed on a circuit board and reflowed. In this method, a solder bump which can correspond to a fine pattern shape of fine pitch of an electronic component is required.

Further, a method of forming a solder bump on a circuit board is known as a plating method, an electroless plating method, a method of printing a paste of a solder powder, and a method of reflow soldering. However, it is difficult to make the solder layer thick by the manufacturing method of the solder bump by the electroless plating method, and it is difficult to apply a current for plating to a complicated circuit by the method of manufacturing the solder bump by the plating method. Moreover, it is difficult to correspond to the fine pitch pattern by the method of printing solder paste. Based on these conditions, as a method of forming solder bumps having a certain and uniform height, a method of attaching solder balls to a circuit has been used.

As a method of attaching a solder ball to an electric circuit, there is known a method in which a compound which imparts adhesiveness is reacted to impart adhesiveness to the surface of a conductive circuit electrode of a circuit board, and solder powder is adhered to the adhesive portion. Subsequently, solder bumps are formed by heating the circuit substrate (Patent Document 1). In addition, as a method of applying this method, a technique of attaching only one solder powder particle to a necessary portion has been developed (see Patent Document 2).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] JP-A-7-7244

[Patent Document 2] JP-A-2008-41803

However, when the height of the solder bumps such as the BGA structure is high, when the wafer is connected to the circuit board by reflow, the molten solder bumps are easily collapsed. Moreover, the wafer sinks unevenly and has a problem of being joined in an inclined state.

In contrast to this, a method in which a solder ball having a high melting point is melted at a high temperature to form a solder bump is used, and a solder having a lower melting point is used. Others, a method of using a solder to plate a metal ball such as copper (copper core solder ball) is also known. By arranging the copper core solder balls to form solder bumps when they are melted, the electronic components are mounted and then the core body is used as a spacer by reflowing, so that a certain distance can be maintained between the electronic components and the circuit board.

However, high melting point solders are limited in their materials and are currently used in high concentration lead compositions. In addition, as for the high-melting-point solder, it is a serious problem that the lead concentration of lead containing 95% or 80% of lead is high, and the α-ray released by the isotope of lead causes malfunction of LSI or the like. Therefore, a completely lead-free high melting point solder is required.

Moreover, the method of using a copper core solder ball is technically difficult to uniformly attach the solder to the ball of the copper core, and there is a problem that the manufacturing cost is remarkably high. Therefore, it is not possible to achieve widespread use.

The present invention has been made in view of the above problems, and an object thereof is to provide a method of manufacturing a circuit board which can be joined without slanting and which can simplify the steps.

The present inventors have made active efforts to review the results in order to solve the above problems, and have completed the present invention. That is, the present invention is as follows.

[1] A method of manufacturing a circuit board, comprising the step of applying a first adhesion-promoting compound to a surface of a terminal portion on a circuit board to form a first adhesive layer, and attaching the core body to the terminal portion. a step of coating the second adhesive layer on the surface of the core body to form a second adhesive layer on the surface of the core body, and attaching the first solder particles to the second adhesive layer on the surface of the core body And the step of melting the first solder particles to form a solder layer on the surface of the core body.

[2] The method for producing a circuit board according to [1], comprising the steps of: applying the first adhesion-imparting compound to the surface of the terminal portion to form the first adhesive layer, a step of adhering the first solder particles to the first adhesive layer by adhering the first solder particles to the first adhesive layer through the second adhesive layer, and melting the first solder particles The step of forming the aforementioned solder layer on the surface of the core.

[3] The method of manufacturing a circuit board according to [1], wherein after the step of attaching the first solder particles to the second adhesive layer, the second solder particles are adhered through the first adhesive layer In the step of forming the solder layer on the surface of the terminal portion, the first solder particles and the second solder particles are simultaneously melted.

[4] The method of manufacturing a circuit board according to [1], wherein the step of attaching the core body to the first adhesive layer and the step of forming the second adhesive layer have a first adhesion The layer attaches the second solder particles to the surface of the terminal portion, and when the step of forming the solder layer is performed, the first solder particles and the second solder particles are simultaneously melted.

[5] The method of manufacturing a circuit board according to [1], wherein the step of forming the first adhesive layer has a step of attaching the second solder particles to a surface of the terminal portion, and forming the solder layer In the step, the first solder particles and the second solder particles are simultaneously melted.

[6] The method of manufacturing a circuit board according to [1], wherein the second solder particles are adhered to the surface of the terminal portion, and the second solder particles are melted on the surface of the terminal portion. a step of forming a solder film thereon, and a step of forming a first adhesive layer by applying a first adhesion-promoting compound to the surface of the terminal portion through the solder film, and forming the solder layer A solder particle is simultaneously melted with the solder film.

[7] The method for producing a circuit board according to [1], comprising the steps of: forming a solder film on the surface of the terminal portion by a plating method; and applying the solder film to the surface of the terminal portion through the solder film A step of forming a first adhesive layer by applying an adhesive compound, and simultaneously forming the solder layer, the first solder particles and the solder film are simultaneously melted.

[8] The method of manufacturing a circuit board according to [3], wherein the second solder particles have an average particle diameter of 1 μm or more and 0.4 times or less the average particle diameter of the first solder particles.

The method of manufacturing a circuit board according to the above aspect, wherein the second solder particles have an average particle diameter of 1 μm or more and 0.5 times or less the average particle diameter of the core body, and are more than the foregoing. The first solder particles are small.

[10] The method for producing a circuit board according to [9], wherein the second solder particles have an average particle diameter of 5 to 10 μm.

[11] The method of manufacturing a circuit board according to [6], wherein the second solder particles have an average particle diameter of 1 μm or more and 1/3 or less of a diameter of the terminal portion.

[12] The method of manufacturing a circuit board according to [7], wherein the solder film is formed to have a thickness of about 3 μm.

The method of manufacturing a circuit board according to any one of the aspects of the present invention, wherein the circuit board having the first adhesive layer is immersed in a dispersion containing the core body The core body is attached to the first adhesive layer.

[14] The method of manufacturing a circuit board according to [2], wherein the circuit board having the first adhesive layer is immersed in a dispersion containing the core body to which the first solder particles are attached, and the adhesion is performed. A core body of a solder particle is attached to the first adhesive layer.

The method of manufacturing a circuit board according to any one of the aspects of the present invention, wherein the circuit board to which the core body having the second adhesive layer is adhered is immersed in the circuit board. In the dispersion liquid of the first solder particles, the first solder particles are attached to the surface of the core body.

[16] The method of manufacturing a circuit board according to [2], wherein the core body having the second adhesive layer is immersed in a dispersion liquid containing the first solder particles, and the first Solder particles are attached to the second adhesive layer to form the core body to which the first solder particles are attached.

[17] The method of manufacturing a circuit board according to any one of [1] to [16], wherein a metal ball is used as the core body.

[18] The method of manufacturing a circuit board according to any one of [1] to [17] wherein the core system is made of copper.

[19] The method of manufacturing a circuit board according to [1], wherein, in the step of forming the first adhesive layer, after forming an insulating layer having an opening portion exposing the terminal portion on the circuit substrate Forming the aforementioned first adhesive layer.

According to the manufacturing method of the present invention, after the core body is adhered to the terminal portion, the first solder particles are adhered to the core body through the second adhesive layer, and the first solder particles are heated and melted to form solder on the surface of the core body. The layer is thus substantially simplified in comparison to the case of using a core body which is plated to adhere to the solder layer on the surface of the solder layer. Further, since the core body serves as a spacer when the electronic component or the like is mounted, the electronic component can be mounted without tilting the posture.

Moreover, according to the manufacturing method of the present invention, after the core body to which the first solder adheres is attached to the terminal portion, the first solder particles are heated and melted to form a solder layer on the surface of the core body, so that the surface is formed by plating or the like. The step of forming the core of the solder layer to which the solder is attached can be greatly simplified. Further, since the core body becomes a spacer when the electronic component or the like is mounted, the electronic component can be mounted without tilting the posture.

As described above, according to the present invention, it is possible to provide a method of manufacturing a circuit board which can join a mounted component without tilting and which can simplify the steps.

(First embodiment)

Hereinafter, a method of manufacturing the circuit board according to the first embodiment of the present invention will be described with reference to the drawings. 1 and 2 are process diagrams for explaining a method of manufacturing a circuit board of the embodiment.

The method of manufacturing the circuit board of the present embodiment is roughly constituted by the steps of forming the first adhesive layer 5 on the terminal portion 2 of the circuit board 1 and attaching the core body 11 to the first adhesive layer 5, thereby making the method of manufacturing the circuit board. The first solder particles 14 are attached to the surface of the core body 11 and the first solder particles 14 are melted to form the solder layer 15.

The preferred embodiments of each step are described in detail below.

The circuit board 1 to which the present invention is applied can be exemplified by laminating a metal plate on a plastic substrate, a plastic film substrate, a glass cloth substrate, a paper matrix epoxy substrate, a ceramic substrate, or the like, or coating the metal substrate. A single-sided circuit board, a double-sided circuit board, a multilayer circuit board, a flexible circuit board, or the like formed by forming a circuit pattern using a conductive material such as a metal on an insulating substrate made of a plastic or a ceramic. Others can also be applied to IC substrates, capacitors, resistors, coils, variable resistors, dual tubes, wafers, and the like.

Fig. 1(a) is a cross-sectional view showing the circuit board 1 used in the embodiment. The circuit board 1 can be exemplified as a ceramic substrate, for example.

A circuit pattern (terminal portion 2) made of, for example, copper or a copper alloy is formed on one surface 1a of the circuit board 1. The step of forming the first adhesive layer 5 on the surface 4 of the terminal portion 2 will be described below.

First, as shown in FIG. 1(b), the opening portion 6 is formed in advance around the terminal portion 2 with a resist (insulating layer) 3. Specifically, the resist layer 3 is formed on the entire surface of the upper surface 1a of the circuit board 1, and is exposed and developed, whereby the resist layer 3 is cured to form the opening portion 6. The opening portion 6 has a configuration in which the terminal portion 2 is exposed. Further, the diameter F of the opening portion 6 and the particle diameter D of the core body 11 are appropriately set.

As the resist layer 3, an insulating resist generally used in the manufacture of a circuit board can be used. When the resist layer 3 has a property of not providing adhesiveness in the step of providing the first adhesive layer 5 to be described later, the material is not limited.

Further, the material of the terminal portion 2 may be copper or a copper alloy. However, the present invention is not limited thereto, and any conductive material which is adhesively obtained by imparting an adhesive property to a later-described step may be used. . These materials are exemplified by, for example, those containing flash gold, Ni, Sn, Ni-Au, Pd, Ag, solder alloy, and the like.

Further, the depth H of the opening portion 6 (the difference between the surface 4 of the terminal portion 2 and the upper surface of the resist layer 3) is appropriately set in accordance with the particle diameter D of the core body 11. The step difference H is preferably smaller than the particle diameter D of the core body 11. When the step difference H is larger than the particle diameter D, it is less preferable because the bumps 16 cannot be formed normally. If the step H is such that the core body does not fall off by the adhesive force in the later-described step, the surface of the electrode which is higher than the surface of the resist layer may have a negative range. However, in consideration of the workability of the step and the function of the core body, it is preferably in the range of 1 μm or more and one-half or less of the particle diameter D. By causing the step difference H to fall within the range, in the later-described step, the core body 11 can be prevented from falling off and a sufficiently high solder bump 16 can be formed. The opening portion 6 is preferably circular, but may be replaced by an elliptical shape or a quadrangular shape.

Next, as shown in FIG. 1(c), the first adhesive layer 5 is formed. First, at least one or two or more of the first adhesion-imparting compounds shown below are dissolved in water or acidic water, and are preferably adjusted to have a slightly acidic pH of about 3 to 4. Thereby an adhesive solution is formed. Next, the first adhesive layer 5 is formed on the surface 4 of the terminal portion 2 by immersing the circuit board 1 in an adhesive solution or applying an adhesive solution on the circuit board 1.

Here, as the first adhesion-imparting compound, a naphthotriazole derivative, a benzotriazole derivative, an imidazole derivative, a benzimidazole derivative, a mercaptobenzothiazole derivative, and a benzo can be used. Thiazolyl fatty acids and the like. These adhesion-imparting compounds are particularly effective against copper, but can also impart adhesion to other conductive materials.

Further, the benzotriazole derivative which is preferably used in the present invention is represented by the formula (1).

【化1】

In the formula (1), R1 to R4 are independently a hydrogen atom, an alkyl group having 1 to 16 carbon atoms (preferably 5 to 16), an alkoxy group, F, Br, Cl, I, a cyano group or an amine group. Or OH group.

Further, the naphthotriazole derivative which is preferably used in the present invention is represented by the formula (2).

[Chemical 2]

Wherein, in the formula (2), R5 to R10 are independently a hydrogen atom, an alkyl group having 1 to 16 carbon atoms (preferably 5 to 16), an alkoxy group, F, Br, Cl, I, a cyano group or an amine group. Or OH group.

Further, the imidazole-based derivative which is preferably used in the present invention is represented by the formula (3).

[化3]

In the formula (3), R11 and R12 are independently a hydrogen atom, an alkyl group having 1 to 16 carbon atoms (preferably 5 to 16), an alkoxy group, F, Br, Cl, I, a cyano group or an amine group. Or OH group.

Further, the benzimidazole-based derivative which is preferably used in the present invention is represented by the formula (4).

【化4】

In the formula (4), R13 to R17 are independently a hydrogen atom, an alkyl group having 1 to 16 carbon atoms (preferably 5 to 16), an alkoxy group, F, Br, Cl, I, a cyano group or an amine group. Or OH group.

Further, the mercaptobenzothiazole-based derivative which is preferably used in the present invention is represented by the formula (5).

【化5】

In the formula (5), R18 to R21 are independently a hydrogen atom, an alkyl group having 1 to 16 carbon atoms (preferably 5 to 16), an alkoxy group, F, Br, Cl, I, a cyano group or an amine group. Or OH group.

Further, the benzothiazole sulfur fatty acid derivative which is preferably used in the present invention is represented by the formula (6).

【化6】

Wherein, in the formula (6), R22 to R26 are independently a hydrogen atom, an alkyl group having 1 to 16 carbon atoms (preferably 1 or 2), an alkoxy group, F, Br, Cl, I, a cyano group or an amine group. Or OH group.

Among these compounds, in the benzotriazole-based derivative represented by the formula (1), R1 to R4 generally have a higher carbon number and more adhesiveness.

Further, in the case of the imidazole-based derivative represented by the general formula (3) and the general formula (4) and the benzimidazole-based derivative R11 to R17, generally, the more the carbon number, the stronger the adhesion.

Further, in the benzothiazole sulfur fatty acid derivative represented by the formula (6), R22 to R26 are preferably a carbon number of 1 or 2.

Further, examples of the substance used for pH adjustment of the adhesive solution include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid. Further, for the organic acid, formic acid, lactic acid, acetic acid, propionic acid, malic acid, oxalic acid, malonic acid, succinic acid, tartaric acid or the like can be used.

The concentration of the first adhesion-imparting compound in the adhesive solution is not particularly limited, but may be appropriately adjusted depending on the solubility and the use condition, and is preferably in the range of 0.05% by mass to 20% by mass based on the total amount of the adhesive solution. By setting the concentration of the first adhesion-imparting compound within this range, the terminal portion 2 can be sufficiently adhered. On the other hand, when the total amount of the adhesive solution is less than 0.05% by mass, sufficient adhesion cannot be provided, and when the total amount of the adhesive solution exceeds 20% by mass, a large amount of the adhesive-imparting compound is consumed, resulting in inefficiency. It is not good.

The treatment temperature at the time of imparting adhesion to the terminal portion 2 is preferably slightly higher than the room temperature. According to this, the formation speed and the amount of formation of the first adhesive layer 5 can be made sufficient. Further, the optimum treatment temperature differs depending on the concentration of the adhesive compound to be applied and the type of the material metal of the terminal portion 2, but is preferably in the range of 30 ° C to 60 ° C. Further, it is preferable to adjust the other conditions so that the immersion time of the adhesive solution is in the range of 5 seconds to 5 minutes.

Further, in the adhesive solution, it is preferable to coexist 50 to 1000 ppm of ionic copper. By causing copper ions to coexist in the above range, the formation efficiency of the first adhesive layer 5, the formation amount, and the like can be improved.

The method of forming the adhesive layer of the present embodiment is not limited to the terminal portion of the circuit board, and can be effectively used as a solder bump portion for connection of the LSI itself, that is, an LSI wafer or a CSP (wafer size package) having a BGA. A bump forming means such as LSI. Moreover, these are of course included in the solder circuit board of the present invention.

Next, as shown in FIG. 1(d), the core body 11 is adhered to the terminal portion 2 through the first adhesive layer 5. This method is described below. At this time, the method of attaching the core body 11 to the first adhesive layer 5 is a method of directly supplying the core body 11 to the first adhesive layer 5 in air or an inert atmosphere, or dispersing the core body 11 in the dispersion liquid. In the case where the slurry is in the state of 41, the slurry is supplied to the first adhesive layer 5.

First, a method of attaching the core body 11 in an air or an inert gas atmosphere will be described. First, the core body 11 is placed in a container filled with air or an inert gas. Next, the circuit board 1 formed up to the first adhesive layer 5 is provided in the container. Next, the container is tilted or vibrated to bring the first adhesive layer 5 into contact with the core body 11. Thereby, the core body 11 is attached to the first adhesive layer 5.

Next, a method of attaching the core body 11 to the liquid will be described. First, as shown in FIG. 3, a dispersion liquid 41 such as water is injected into the container 40, and the core body 11 is further added to the dispersion liquid 41. Next, the container 40 is tilted so that the dispersion liquid 41 and the core body 11 are opposed to each other, and the circuit board 1 is placed in the container so as not to come into contact with the core body 11 with the dispersion liquid 41. Subsequently, the first adhesive layer 5 in the dispersion 41 is brought into contact with the core body 11 by shaking the container 40 to the left and right. Thereby, the core body 11 is attached to the first adhesive layer 5.

As described above, by attaching the core body 11 to the liquid, the core body 11 adheres to the non-adhesive portion due to static electricity, and the core body 11 can be prevented from agglomerating due to static electricity. Therefore, it is particularly preferable to use this method for a fine pitch circuit board or when using fine powder. Further, the method of attaching the core body 11 is not limited to the method of adhering to the liquid, and it is also possible to independently adopt an appropriate method in each step depending on the size of the core body 11 or the like.

Further, the material of the core body 11 is preferably copper. However, if it has a melting point higher than the melting point of the first solder particles 14, and the adhesive property is obtained by the second adhesive property, the other may be used. These materials may be, for example, a material containing an alloy of Ni, Sn, Ni-Au, Au-Sn, or Au-Si, in addition to copper.

Further, the average particle diameter D of the core body 11 is preferably selected depending on the size of the terminal portion 2 to be attached, but is preferably in the range of 20 μm to 200 μm.

Next, a second adhesive layer 13 is formed as shown in FIG. 1(e).

The method of forming the second adhesive layer 13 can directly use the method of forming the first adhesive layer 5, using the same compound as the first adhesive-imparting compound as the second adhesive-imparting compound, and can be in the same manner as the first adhesive layer 5. The formation method is the same under the same conditions. In other words, the circuit board 1 is immersed in an adhesive solution of a compound (second adhesion-imparting compound) adjusted in the same manner as the first adhesive-imparting compound, or formed by coating the surface 12 of the core body 11 by coating. The second adhesive layer 13.

Next, as shown in FIG. 1(f), the first solder particles 14 are adhered to the surface 12 of the core body 11 through the second adhesive layer 13. This method is described below.

The method of attaching the first solder particles 14 to the second adhesive layer 13 is to directly supply the first solder particles 14 to the second adhesive layer 13 in air or an inert atmosphere, or to disperse the first solder particles 14. A method in which the dispersion liquid 41 is in a slurry state, and the slurry is supplied onto the second adhesive layer 13 or the like.

First, a method of attaching the first solder particles 14 in an inert gas atmosphere will be described. First, the first solder particles 14 are poured into a container filled with air or an inert gas. Next, the circuit board 1 formed up to the second adhesive layer 13 is provided in the container. Next, the container is tilted or vibrated to bring the second adhesive layer 13 into contact with the first solder particles 14. Thereby, the first solder particles 14 are attached to the second adhesive layer 13.

Next, a method of attaching the first solder particles 14 to the liquid will be described. First, as shown in FIG. 3, a dispersion liquid 41 such as water is injected into the container 40, and the first solder particles 14 are added to the dispersion liquid 41. Next, the container 40 is tilted so that the dispersion liquid 41 and the first solder particles 14 are turned to one side, and the circuit board 1 is placed in the container so as not to be in contact with the first solder particles 14 . Subsequently, the second adhesive layer 13 in the dispersion 41 is brought into contact with the first solder particles 14 by shaking the container 40 to the left and right. Thereby, the first solder particles 14 are attached to the second adhesive layer 13.

Further, the method of attaching the first solder particles 14 is not limited to the method of adhering to the liquid, and it is also possible to independently adopt a suitable method in each step depending on the size and conditions of the first solder particles 14.

Further, the first solder particles 14 are smaller in particle diameter than the solder bumps 20 or the core bodies 11. The particle diameter E of the first solder particles 14 corresponds to the particle diameter D of the core body 11, and may be appropriately set so that a plurality of first solder particles 14 are attached to one core body 11. That is, the average particle diameter E of the first solder particles 14 is preferably 1 μm or more and smaller than one-half of the average particle diameter D of the core body 11. By causing the particle diameter E of the first solder particles 14 to fall within the range, a plurality of first solder particles 14 can be attached to one core body 11. On the other hand, when the particle diameter E of the first solder particles 14 is less than 1 μm, the amount of solder is insufficient, which is not preferable. When the particle diameter E of the first solder particles 14 is more than one-half of the average particle diameter D of the core body 11, it is not preferable to attach a sufficient number of the first solder particles 14 to the single core body 11.

Further, the metal composition of the first solder particles 14 is, for example, a Sn-Pb system, a Sn-Pb-Ag system, a Sn-Pb-Bi system, a Sn-Pb-Bi-Ag system, or a Sn-Pb-Cd system. Further, in view of the recent exclusion of Pb from industrial waste, it is preferably a Sn-In system, a Sn-Bi system, an In-Ag system, an In-Bi system, a Sn-Zn system, or a Sn-Ag which do not contain Pb. , Sn-Cu, Sn-Sb, Sn-Au, Sn-Bi-Ag-Cu, Sn-Ge, Sn-Bi-Cu, Sn-Cu-Sb-Ag, Sn-Ag -Zn system, Sn-Cu-Ag system, Sn-Bi-Sb system, Sn-Bi-Sb-Zn system, Sn-Bi-Cu-Zn system, Sn-Ag-Sb system, Sn-Ag-Sb-Zn System, Sn-Ag-Cu-Zn system, Sn-Zn-Bi system.

Specific examples of the metal composition are eutectic solders having a Sn content of 63% by mass and a Pb of 37% by mass (hereinafter referred to as 63Sn/37Pb), and are listed as 62Sn/36Pb/2Ag, 62.6Sn/37Pb/0.4Ag, 60Sn. /40Pb, 50Sn/50Pb, 30Sn/70Pb, 25Sn/75Pb, 10Sn/88Pb/2Ag, 46Sn/8Bi/46Pb, 57Sn/3Bi/40Pb, 42Sn/42Pb/14Bi/2Ag, 45Sn/40Pb/15Bi, 50Sn/32Pb /18Cd, 48Sn/52In, 43Sn/57Bi, 97In/3Ag, 58Sn/42In, 95In/5Bi, 60Sn/40Bi, 91Sn/9Zn, 96.5Sn/3.5Ag, 99.3Sn/0.7Cu, 95Sn/5Sb, 20Sn/80Au , 90Sn/10Ag, 90Sn/7.5Bi/2Ag/0.5Cu, 97Sn/3Cu, 99Sn/1Ge, 92Sn/7.5Bi/0.5Cu, 97Sn/2Cu/0.8Sb/0.2Ag, 95.5Sn/3.5Ag/1Zn, 95.5 Sn/4Cu/0.5Ag, 52Sn/45Bi/3Sb, 51Sn/45Bi/3Sb/1Zn, 85Sn/10Bi/5Sb, 84Sn/10Bi/5Sb/1Zn, 88.2Sn/10Bi/0.8Cu/1Zn, 89Sn/4Ag/7Sb , 88Sn/4Ag/7Sb/1Zn, 98Sn/1Ag/1Sb, 97Sn/1Ag/1Sb/1Zn, 91.2Sn/2Ag/0.8Cu/6Zn, 89Sn/8Zn/3Bi, 86Sn/8Zn/6Bi, 89.1Sn/2Ag/ 0.9Cu/8Zn, etc. Further, the first solder particles 14 of the present embodiment may be a mixture of two or more types of first solder particles having different compositions.

Next, the core body 11 and the first solder particles 14 are fixedly attached. The fixed adhesion is a reaction between the terminal portion 2 and the first solder particles 14 to diffuse the constituent material of the terminal portion 2 to the side of the first solder particles 14 . By performing this reaction, the core body 11 and the first solder particles 14 are fixed to each other. The temperature at which the adhesion is fixed is preferably in the range of -50 ° C to +50 ° C of the melting point of the solder, more preferably in the range of -30 ° C to + 30 ° C. When the fixed adhesion temperature is within this range, the first solder particles 14 are not melted, or even if the internal melting is assumed, the effect of the oxide film existing on the surface does not melt out. Therefore, the shape of the first solder particles 14 can be directly maintained and fixedly attached.

Subsequently, a water-soluble flux is applied onto the circuit substrate 1. As the water-soluble flux, for example, a flux described in JP-A-2004-282062 can be used. The surface of the first solder particles 14 and the oxide film on the surface 4 of the terminal portion 2 can be removed by using a water-soluble flux.

Next, as shown in FIG. 2(a), a reflow step is performed to form solder bumps 16. This method is described below.

First, after the circuit board 1 is dried, a reflow step is performed to melt the first solder particles 14. The heating temperature at this time is preferably in the range of 200 ° C to 300 ° C, preferably in the range of 10 ° C to 50 ° C. By heating at these temperatures, the molten solder of the first solder particles 14 can be sufficiently reacted with the surface 4 of the terminal portion 2 or the surface 12 of the core body 11 to form a diffusion layer.

Accordingly, the first solder particles 14 are fused in parallel through the entire surface 12 of the core body 11. Therefore, the terminal portion 2 is strongly connected to the core body 11, and the electronic component 22 mounted thereon is stably connected to the core body 11. After the reflow step, the circuit board 1 is washed to remove residual flux. Thereby, the solder bumps 16 are formed on the terminal portion 2.

Next, as shown in FIGS. 2(b) to 2(d), the electronic component 22 is mounted on the circuit board 1. The method for this is explained below.

First, as shown in FIG. 2(b), the terminal portion 24 is aligned with the position of the solder bump 16, and the electronic component 22 is placed on the circuit board 1. The electronic component 22 is roughly configured by the electronic component body 23 and the terminal portion 24. The terminal portion 24 is provided on one surface side of the electronic component body 23, and a plating portion 25 is formed on the surface of the terminal portion 24.

Next, the electronic component 22 is mounted on the circuit board 1 to bring the plating portion 25 into contact with the solder layer 15. This state is shown in Fig. 2(c). Next, as shown in FIG. 2(d), a reflow step is performed to melt the solder layer 15, and the terminal portion 24 and the terminal portion 2 are solder-bonded. Thereby, the electronic component 22 is mounted on the circuit board 1.

According to the method of manufacturing the circuit board 1 of the present embodiment, the distance between the electronic component 22 and the circuit board 1 can be kept constant by using the core body 11 as a spacer. Therefore, the problem that the mounted electronic component 22 is unevenly deposited on the circuit board 1 can be solved, and the height of the terminal portion 2 can be made constant, and the circuit board 1 having high reliability can be obtained. Further, since the first solder particles 14 are adhered to the core body 11 through the second adhesive layer 13, the expensive copper core solder balls are not used. Therefore, cost reduction and simplification of steps can be achieved. Further, since it is not necessary to use a high melting point solder containing a high concentration of lead, it is possible to solve the problem of malfunction caused by the alpha ray emitted from the Pb isotope. Further, the manufacturing method of the present embodiment is a method suitable for a fine circuit substrate, and can provide an electronic device having a high degree of integration and high reliability.

Further, after the resist layer 3 having the opening portion 6 is formed on the circuit board 1, since the adhesive layer 5 is formed, the first adhesive layer 5 is not formed in portions other than the terminal portion 2. Thereby, the core body 11 can be selectively attached to the terminal portion 2. Further, since the core body 11 is attached to the opening portion 6, even when the adhesion force of the first adhesive layer 5 is weak, the core body 11 can be prevented from falling out of the opening portion 6. Thereby, the core body 11 can be surely attached to all of the terminal portions 2.

Further, in the dispersion liquid 41 including the core body 11, by attaching the core body 11 to the first pressure-sensitive adhesive layer 5, the adhesion amount of the core body 11 to each of the terminal portions 2 can be made uniform. Thereby, for example, one core body 11 can be surely attached to one terminal portion 2.

Further, in the dispersion liquid 41 including the first solder particles 14, by attaching the first solder particles 14 to the second adhesive layer 13, the amount of adhesion of the first solder particles 14 to the respective core bodies 11 can be made uniform.

Further, by using the metal ball as the core body 11, the conduction between the electronic component 22 and the terminal portion 2 can be ensured. In particular, when the core body 11 is made of copper, the second adhesive layer 13 can be easily formed while ensuring conduction.

(Second embodiment)

Hereinafter, a method of manufacturing the circuit board 1 according to the second embodiment of the present invention will be described with reference to the drawings.

This embodiment is different from the first embodiment in that after the first solder particles 14 are adhered to the surface 12 of the core body 11 through the second adhesive layer 13, the second solder particles 114 are attached to the second solder particles 114 as shown in Fig. 4(g). On the first adhesive layer 5. The details are explained below.

First, as shown in FIGS. 4(a) to 4(f), the first solder particles 14 are adhered to the surface 12 of the core body 11 through the second adhesive layer 13. Since the steps up to now are the same as those in the first embodiment, the detailed description thereof will be omitted.

Next, as shown in FIG. 4(g), the second solder particles 114 are attached to the first adhesive layer 5. The method of attachment is the same as the method of attaching the core body 11 described above, and the detailed description thereof will be omitted. At this time, the average particle diameter of the second solder particles 114 is preferably 1 μm or more and 0.4 times or less the average particle diameter E of the first solder particles 14 . By causing the particle diameter of the second solder particles 114 to fall within the range, a sufficient amount of the second solder particles 114 can enter between the first solder particles 14 and the first adhesive layer 5.

On the other hand, if the particle diameter of the second solder particles 114 is less than 1 μm, the molten solder cannot sufficiently pass between the core body 11 and the terminal portion 2 in the subsequent reflow step. Further, if the particle diameter of the second solder particles 114 exceeds 0.4 times the average particle diameter E of the first solder particles 14, in the subsequent reflow step, a large amount of molten solder passes between the core body 11 and the terminal portion 2 or Since the second solder particles cannot enter a specific position, the size of the solder bumps 16 to be described later is not uniform.

Next, the core body 11, the first solder particles 14 and the second solder particles 114 are fixedly attached. Subsequently, the first solder particles 14 and the second solder particles 114 are simultaneously melted by reflow to form the solder layer 15. Subsequently, the circuit board 1 of the present embodiment is manufactured by performing the same steps as those of the first embodiment.

According to the method of manufacturing the circuit board 1 of the present embodiment, after the first solder particles 14 are adhered to the surface 12 of the core body 11 through the second adhesive layer 13, the first solder layer 5 is transmitted through the first adhesive layer 5 to be smaller than the first solder particles 14. The second solder particles 114 are attached to the terminal portion 2. Thereby, the second solder particles 114 can be made to enter the gap between the core body 11 and the terminal portion 2. Therefore, the core body 11 and the terminal portion 2 can be surely connected in the reflow step.

(Third embodiment)

Hereinafter, a method of manufacturing the circuit board 1 according to the third embodiment of the present invention will be described with reference to the drawings.

This embodiment differs from the first embodiment in that after the core body 11 is adhered to the terminal portion 2 through the first adhesive layer 5, the second solder particles 114 are attached to the first electrode as shown in FIG. 5(e). Adhesive layer 5 on. The details are explained below.

First, as shown in FIGS. 5(a) to (d), the core body 11 is attached to the first adhesive layer 5. Since the steps up to now are the same as those in the first embodiment, the detailed description thereof will be omitted.

Next, as shown in FIG. 5(e), the second solder particles 114 are attached to the first adhesive layer 5. Since the attachment method is the same as the method of attaching the core body 11 described above, the detailed description thereof will be omitted.

In this case, the average particle diameter of the second solder particles 114 is preferably 1 μm or more and 0.5 times or less the average particle diameter D of the core body 11 and smaller than the average particle diameter E of the first solder particles 14 . In the range of 5~10μm. By causing the particle diameter of the second solder particles 114 to fall within the range, a sufficient amount of the second solder particles 114 can enter between the first solder particles 14 and the first adhesive layer 5.

Further, at this time, the second solder particles 114 having different particle diameters may be attached to the first adhesive layer 5 at a respective particle diameter. Accordingly, the second solder particles 114 can uniformly cover the first adhesive layer 5.

On the other hand, when the particle diameter of the second solder particles 114 is less than 1 μm, the molten solder cannot sufficiently pass between the core body 11 and the terminal portion 2 in the subsequent reflow step. Further, when the particle diameter of the second solder particles 114 exceeds 0.5 times the average particle diameter E of the first solder particles 14, in the subsequent reflow step, since a large amount of molten solder passes between the core body 11 and the terminal portion 2, The size of the solder bumps 16 described later is not uniform.

Next, as shown in FIG. 5(f), the second adhesive layer 13 is formed so as to cover the core body 11 and the second solder particles 114. The method of forming the second adhesive layer 13 here is the same as the method of forming the second adhesive layer 13 of the first embodiment, and thus detailed description thereof is omitted here.

Next, as shown in FIG. 5(g), the first solder particles 14 are adhered to the surface 12 of the core body 11 through the second adhesive layer 13.

Next, the core body 11, the first solder particles 14 and the second solder particles 114 are fixedly attached. Subsequently, the first solder particles 14 and the second solder particles 114 are simultaneously melted by reflow to form the solder layer 15. Subsequently, the circuit board 1 of the present embodiment is manufactured by performing the same steps as those of the first embodiment.

According to the method of manufacturing the circuit board 1 of the present embodiment, after the core body 11 is adhered to the terminal portion 2 through the first adhesive layer 5, the second solder particles 114 smaller than the first solder particles 14 are attached to the terminal portion 2 . Thereby, the second solder particles 114 can be made to enter the gap between the core body 11 and the terminal portion 2. Further, in this step, since the second solder particles 114 are fixedly attached to each other in the fixing and attaching step, the second solder particles 114 can be stably adhered to the terminal portion 2. Therefore, the core body 11 and the terminal portion 2 can be more reliably connected in the reflow step.

(Fourth embodiment)

Hereinafter, a method of manufacturing the circuit board 1 according to the fourth embodiment of the present invention will be described with reference to the drawings.

This embodiment is different from the first embodiment in that the second solder particles 114 are adhered to the terminal portion 2, and the first adhesive layer 5 and the core body 11 are sequentially formed, as shown in FIG. 6(c). The second adhesive layer 13. The details are explained below.

First, as shown in FIGS. 6(a) to 6(b), the terminal portion 2 is opened. Since the steps up to now are the same as those in the first embodiment, the detailed description thereof will be omitted. Next, as shown in FIG. 6(c), an adhesive portion (not shown) is formed on the surface 4 of the terminal portion 2. Next, the second solder particles 114 are attached to the surface 4 of the terminal portion 2 through the adhesive portion.

In this case, the average particle diameter of the second solder particles 114 is preferably 1 μm or more and 0.5 times or less the average particle diameter D of the core body 11 and smaller than the average particle diameter E of the first solder particles 14 . Within the range of 5~10μm. By causing the particle diameter of the second solder particles 114 to fall within the range, a sufficient amount of the second solder particles 114 can enter between the first solder particles 14 and the first adhesive layer 5. Further, by setting the particle diameter of the second solder particles 114 within the range, the solder bumps 16 to be described later can be formed in a uniform size.

On the other hand, if the particle diameter of the second solder particles 114 is less than 1 μm, the molten solder does not sufficiently pass between the core body 11 and the terminal portion 2 in the subsequent reflow step. Further, when the particle diameter of the second solder particles 114 exceeds 0.5 times the average particle diameter E of the first solder particles 14, in the subsequent reflow step, since a large amount of molten solder passes between the core body 11 and the terminal portion 2, The size of the solder bumps 16 described later is not uniform.

Next, as shown in FIG. 6(d), the first adhesive layer 5 is formed so as to cover the surface 4 of the terminal portion 2 and the second solder particles 114. Since the method of forming the first adhesive layer 5 is the same as that of the first embodiment, a detailed description thereof will be omitted.

Subsequently, after the core body 11 is attached to the terminal portion 2 through the first adhesive layer 5 as shown in FIG. 6(e), the second adhesive layer 13 is formed as shown in FIG. 6(f) by coating the core body 11. . Subsequently, as shown in FIG. 6(g), the first solder particles 14 are adhered to the surface 12 of the core body 11 through the second adhesive layer 13. Since these steps are the same as those of the first embodiment, the details thereof are omitted here.

Next, the core body 11, the first solder particles 14 and the second solder particles 114 are fixedly attached. Subsequently, the first solder particles 14 and the second solder particles 114 are simultaneously melted by reflow to form the solder layer 15. Subsequently, the circuit board 1 of the present embodiment is manufactured by performing the same steps as those of the first embodiment.

According to the method of manufacturing the circuit board 1 of the present embodiment, since the core body 11 is placed on the second solder particles 114, the second solder particles 114 and the core body 11 can be firmly fixed by the fixed adhesion step. Therefore, the falling off of the core body 11 at the time of reflow can be prevented. Further, since the melted second solder particles 114 are surely passed between the core body 11 and the terminal portion 2 during the reflow, the core body 11 and the terminal portion 2 can be reliably connected.

(Fifth Embodiment)

Hereinafter, a method of manufacturing the circuit board 1 according to the fifth embodiment of the present invention will be described with reference to the drawings.

In the present embodiment, as shown in FIG. 7(c), unlike the first embodiment, after the second solder particles 114 are adhered to the terminal portion 2, the second solder particles 114 are reflowed to form the solder film 114a. The first adhesive layer 5, the core body 11, and the second adhesive layer 13 are sequentially formed. The details are explained below.

First, as shown in FIGS. 7(a) to 7(b), the terminal portion 2 is opened. Since the steps up to now are the same as those in the first embodiment, the detailed description thereof will be omitted. Next, an adhesive portion (not shown) is formed on the surface 4 of the terminal portion 2. Next, the second solder particles 114 are attached to the surface 4 of the terminal portion 2 through the adhesive portion. This state is shown in Fig. 7(c).

At this time, the average particle diameter of the second solder particles 114 is preferably 1 μm or more and 1/3 or less of the diameter F of the terminal portion 2 . By making the particle diameter of the second solder particles 114 fall within the range, in the subsequent reflow step, the film 114a having a sufficiently flat surface can be formed.

On the other hand, if the particle diameter of the second solder particles 114 is less than 1 μm, the molten solder cannot sufficiently pass between the core body 11 and the terminal portion 2 in the subsequent reflow step. Further, when the particle diameter of the second solder particles 114 exceeds 1/3 of the diameter F of the terminal portion 2, the solder film 114a having a convex surface is formed in the subsequent reflow step. Therefore, in the subsequent steps, it is difficult to attach the core body 11 and it is not preferable.

Next, as shown in FIG. 7(d), the second solder particles 114 are reflowed. Thereby, the solder film 114a is formed so as to cover the surface 4 of the terminal part 2.

At this time, the solder film 114a is not limited to the above-described Super Just Fit (a method of reflowing the solder powder adhered to the adhesive portion), and may be formed by electroplating. When the solder film 114a is formed by electroplating, the thickness of the solder film 114a can be set to about 3 μm. In order to stably obtain the improvement of the fixing adhesion in the fixing and attaching step of the present embodiment, it is preferably 0.5 μm or more. Further, in the case of 1 μm or more, it is preferable to carry out a more stable fixation. Further, although the upper limit of the thickness does not directly affect the fixing adhesion in the fixing and attaching step, it is preferably 10 μm or less in terms of an economical surface. According to this method, the solder film 114a can be formed with a uniform thickness, so that the solder bumps 16 can be formed at a uniform height.

Next, as shown in FIG. 7(e), the first adhesive layer 5 is formed so as to cover the solder film 114a, and then the core body 11 is adhered to the terminal portion 2 through the first adhesive layer 5 and the solder film 114a. Since the method of forming the first adhesive layer 5 is the same as that of the first embodiment, the details thereof are omitted here.

Subsequently, as shown in FIG. 7(e), after the core body 11 is adhered to the terminal portion 2 through the first adhesive layer 5, as shown in FIG. 7(f), the second adhesive is formed so as to cover the core body 11. Layer 13. Subsequently, as shown in FIG. 7(g), the first solder particles 14 are adhered to the surface 12 of the core body 11 through the second adhesive layer 13. Since these steps are the same as those of the first embodiment, the details thereof are omitted here.

Next, the core body 11, the first solder particles 14 and the second solder particles 114 are fixedly attached. Subsequently, the first solder particles 14 and the solder film 114a are simultaneously melted by reflow to form the solder layer 15. Subsequently, the circuit board 1 of the present embodiment is manufactured by performing the same steps as those of the first embodiment.

According to the method of manufacturing the circuit board 1 of the present embodiment, since the core body 11 is placed on the solder film 114a, the solder film 114a and the core body 11 can be firmly fixed by the fixed adhesion step. Therefore, the falling off of the core body 11 at the time of reflow can be prevented. Further, since the molten solder film 114a can surely pass between the core body 11 and the terminal portion 2 during the reflow, the core body 11 and the terminal portion 2 can be reliably connected.

These manufacturing methods can prevent the core body 11 from falling off and have an effect of improving the yield. The manufacturing method is selected such that the thermal history of the circuit substrate is different depending on the steps, and therefore it is preferably selected depending on the type, shape, electrode size, and the like of the circuit substrate to be used.

(Sixth embodiment)

Hereinafter, a method of manufacturing the circuit board 1 according to the sixth embodiment of the present invention will be described with reference to the drawings. The present embodiment differs from the first embodiment in that, in the step of the present invention, the core body 30 to which the first solder particles are attached is formed in advance, and then the core body 30 to which the first solder particles are attached is attached to the first adhesive layer 5. Therefore, the following description will only explain the part, and the description of the entire steps will be omitted.

First, adhesion is applied to the surface 12 of the core body 11 by using the second adhesion-imparting compound to form the second adhesive layer 13. Next, in the air, in an inert gas atmosphere, or in the dispersion 41 containing the first solder particles 14, the first solder particles 14 are adhered to the second adhesive layer 13 to form an adhesion as shown in Fig. 8(a). The core body 30 of the first solder particles. The core body 30 to which the first solder particles are attached is composed of a second adhesive layer 13 formed on the surface 12 of the core body 11 and first solder particles 14 which are adhered to the surface 12 of the core body 11 through the second adhesive layer 13.

In the present embodiment, the step of forming the second adhesive layer 13 on the surface 12 of the core body 11 is preferably performed in the air, and the step of attaching the first solder particles 14 to the second adhesive layer 13 is preferably in the dispersion 41. get on.

Next, similarly to the steps shown in FIGS. 1(a) to 1(c) of the first embodiment, the first adhesive layer 5 is formed so as to cover the surface of the terminal portion 2 of the circuit board 1. Next, as shown in FIG. 8(b), the core body 30 to which the first solder particles are attached, which is formed in advance, is attached to the first adhesive layer 5. This method is described below.

First, the core body 30 to which the first solder particles are attached in an air or an inert gas atmosphere will be described. First, the core body 30 to which the first solder particles are attached is placed in a container filled with air or an inert gas. Next, the circuit board 1 formed up to the first adhesive layer 5 is provided in the container. Next, the container is tilted or vibrated to bring the first adhesive layer 5 into contact with the core body 30 to which the first solder particles are attached. Thereby, the core body 30 to which the first solder particles are attached is attached to the first adhesive layer 5.

Next, a method of attaching the core body 30 to which the first solder particles are attached in the liquid will be described. First, as shown in FIG. 3, a dispersion liquid 41 such as water is injected into the container 40, and the core body 30 to which the first solder particles are attached is added to the dispersion liquid 41. Next, the container 40 is tilted so that the dispersion liquid 41 and the core body 30 to which the first solder particles are attached are placed one side, and the circuit board 1 is placed on the container so as not to be in contact with the dispersion liquid 41 and the core body 30 to which the first solder particles are attached. Inside. Subsequently, the first adhesive layer 5 in the dispersion 41 is brought into contact with the core body 30 to which the first solder particles are attached by shaking the container 40 to the left and right. Thereby, the core body 30 to which the first solder particles are attached is attached to the first adhesive layer 5.

Subsequently, similarly to the steps shown in Figs. 2(a) to 2(d) of the first embodiment, the first solder particles 14 are melted, and the solder layer 15 is formed on the surface 12 of the core body 11. Subsequently, the electronic component 22 is mounted on the circuit substrate 1.

According to the manufacturing method of the present embodiment, in addition to the effects similar to those in the first embodiment, the following effects are obtained.

In other words, in the method of manufacturing the circuit board 1 of the present embodiment, after the core body 30 to which the first solder particles are attached is attached to the terminal portion 2, the first solder particles 14 are heated and melted. Thereby, the solder layer 15 can be formed on the surface 12 of the core body 11, and the steps can be greatly simplified as compared with the case where the surface is solder-plated with a solder-coated core.

Further, since the core body 11 serves as a spacer when the electronic component 22 is mounted, the electronic component can be mounted without tilting the posture of the electronic component 22.

Further, since the first adhesive layer 5 is formed after the resist layer 3 having the opening portion 6 is formed on the circuit board 1, the first adhesive layer 5 is not formed in portions other than the terminal portion 2. Thereby, the core body 30 to which the first solder particles are attached can be selectively attached to the terminal portion 2. Further, since the core body 30 to which the first solder particles are attached is attached to the opening portion 6, even when the adhesion force of the first adhesive layer 5 is weak, the core body 30 to which the first solder particles are attached can be prevented from falling off to the opening. Outside the Ministry 6. Thereby, the core body 30 to which the first solder particles are attached can be surely attached to all of the terminal portions 2.

Further, in the dispersion 41 including the core body 30 to which the first solder particles are attached, the core body 30 to which the first solder particles are attached is adhered to the first adhesive layer 5, whereby the core body 30 to which the first solder particles are attached can be attached. The amount of adhesion to each terminal portion 2 is uniform. According to this, it is also possible to reliably attach one core body 30 to which the first solder particles are attached to one terminal portion 2.

Further, in the dispersion liquid 41 including the first solder particles 14, by attaching the first solder particles 14 to the second adhesive layer 13, the amount of adhesion of the first solder particles 14 to the respective core bodies 11 can be made uniform. Further, the step can be greatly simplified as compared with the case where a solder layer is formed by plating or the like on the surface of the core body.

[Examples]

The invention is illustrated by the following examples, but the invention is not limited to the examples.

(Example 1)

First, a pure Cu sphere having a particle diameter of 50 μm was prepared as the core body 11. Next, a circuit board 1 of about 1000 terminal portions 2 made of copper having a diameter of 80 μm was prepared, and an insulating resist layer 3 having a thickness of 20 μm was formed by conventional photolithography. Thereby, a circular opening portion 6 having a diameter of 80 μm which is configured to expose the terminal portion 2 is formed. Next, a 2% by mass aqueous solution of an imidazole compound in which the alkyl group of R12 of the formula (3) is C ₁₁ H ₂₃ and R11 is a hydrogen atom is prepared as an adhesive solution containing the first adhesion-imparting compound, and the pH is adjusted with acetic acid. Adjust to about 4. Then, the adhesive solution was heated to 40 ° C, and the circuit substrate 1 pretreated with an aqueous hydrochloric acid solution was immersed therein for 3 minutes to form the first adhesive layer 5 so as to cover the surface 4 of the terminal portion 2.

Next, a particle attachment device having an internal size of 200 mm × 120 mm × 150 mm was prepared. Further, in the particle adhering device, the container 40 having the inlet port is provided, and the circuit board 1 can be placed in the horizontal direction. Next, 1600 ml of water and about 400 g of a core body 11 composed of copper and having an average particle diameter of 50 μm were placed in the vessel 40. Next, the solder particle adhesion device is tilted, and the water and the core body 11 are placed against one side of the container 40, and then the circuit board 1 is placed in the container 40 so as not to contact the core body 11. Subsequently, the container 40 is shaken left and right by 30° for 30 to 60 seconds, whereby the core body 11 is attached to the circuit board 1 through the first adhesive layer 5. At this time, the shaking period is 10 seconds/time.

Subsequently, the circuit board 1 is taken out from the apparatus, washed gently with pure water, and the circuit board 1 is dried.

Next, the second adhesive layer 13 is formed on the surface 12 of the core body 11 by using the above-mentioned adhesive compound solution.

Next, 1600 ml of water and 400 g of the first solder particles 14 having an average particle diameter of 10 μm of a composition of 96.5 Sn/3.5 Ag were placed in the solder particle adhering device. Next, the solder particle adhering device is tilted, and the water and the first solder particles 14 are placed against one side of the container 40, and then the circuit board 1 is placed in the container so as not to contact the first solder particles 14. Subsequently, the container 40 is shaken left and right by 30° for 30 to 60 seconds, whereby the first solder particles 14 are adhered to the core body 11 through the second adhesive layer 13. At this time, the shaking period is 5 seconds/time.

Subsequently, the circuit board 1 is taken out from the apparatus, washed gently with pure water, and the circuit board 1 is dried.

Next, the circuit board 1 was placed in an oven at 180 ° C and heated for 20 minutes to fix the core body 11 and the first solder particles 14 to each other. Next, a flux spray was applied onto the surface of the circuit board 1, and the circuit board 1 was placed in a reflow furnace for 3 minutes, and heated in a nitrogen atmosphere at 240 ° C to form a solder having a height of about 53 μm on the terminal portion 2. Bump 16.

As a result, the height deviation of the solder bumps 16 is represented by a standard deviation of 1.5 μm, which is the same as the particle diameter deviation of the core body 11. Further, the terminal portion 2 to which the solder bumps 16 were not attached was not found.

(Example 2)

The conditions before the first solder particles 14 were attached to the core body 11 were carried out in the same manner as in Example 1 except that the particle diameter of the core body 11 was 50 μm and the particle diameter of the first solder particles 14 was 20 μm.

Subsequently, by the same procedure, the second solder particles 114 having a particle diameter of 10 μm are adhered to the terminal portion 2 in the water through the second adhesive layer 13.

Subsequently, the solder bumps 16 were produced by washing, drying, and reflowing in the same manner as in the first embodiment.

(Example 3)

In the same manner as in the first embodiment, the particle size of the core body 11 was 50 μm, and the step of attaching the core body 11 to the first pressure-sensitive adhesive layer 5 was carried out.

Subsequently, the second solder particles 114 having a particle diameter of 5 μm are attached to the first adhesive layer 5 in the atmosphere. Subsequently, the first solder particles 14 were adhered to the core body 11 in water except that the particle diameter of the first solder particles 14 was 20 μm.

Subsequently, the solder bumps 16 were produced by washing, drying, and reflowing in the same manner as in the first embodiment.

(Example 4)

In the same manner as in the first embodiment, the resist layer 3 and the opening portion 6 in which the terminal portion 2 is exposed are formed, and then the second solder particles 114 having a particle diameter of 10 μm are adhered to the surface 4 of the terminal portion 2 through the adhesive portion. Subsequently, the solder bumps 16 were produced in the same manner as in Example 1 except that the particle diameter of the core body 11 was 50 μm and the particle diameter of the first solder particles 14 was 20 μm.

(Example 5)

In the same manner as in the first embodiment, the resist layer 3 and the opening portion 6 in which the terminal portion 2 is exposed are formed, and then the second solder particles 114 having a particle diameter of 10 μm are adhered to the surface 4 of the terminal portion 2 through the adhesive portion. Subsequently, the solder bumps 16 were produced in the same manner as in Example 1 except that the particle diameter of the core body 11 was 50 μm and the particle diameter of the first solder particles 14 was 20 μm.

(Example 6)

In the same manner as in the first embodiment, after forming the resist layer 3 and the opening portion 6 in which the terminal portion 2 is exposed, a tin alloy plating layer having a thickness of 3 μm is formed by coating the terminal portion 2 by electroless plating. Subsequently, the solder bumps 16 were produced in the same manner as in Example 1 except that the particle diameter of the core body 11 was 50 μm and the particle diameter of the first solder particles 14 was 20 μm.

As a result of the second embodiment to the sixth embodiment, as a result of any of the solder bumps 16, it is understood that the core body 11 in any of the fixed adhesion step and the reflow step is peeled off, and the terminal portion to which the solder bump 16 is not attached is not found. 2.

[Industry possible use]

The solder bump formed by the method can be formed without using a high melting point solder containing a large amount of lead to achieve lead-free, and can also solve the problem of malfunction due to the alpha ray from the Pb isotope. Moreover, since the solder bumps having the core body in the core are not produced by using the expensive copper core solder balls, the problem of uneven height of the solder bumps can be solved at a low cost, and the wafers are reflowed at the time of mounting the wafers. The problem of sinking. The method is a method suitable for a fine circuit substrate, and can provide an electronic device with high integration and high reliability.

1. . . Circuit substrate

1a. . . Above the circuit board

2. . . Terminal part

3. . . Resist layer

4. . . Terminal surface

5. . . First adhesive layer

6. . . Opening

11. . . Nuclear body

12. . . Nuclear surface

13. . . Second adhesive layer

14. . . First solder particle

15. . . Solder layer

16, 20. . . Solder bump

twenty two. . . Electronic parts

twenty three. . . Electronic component body

twenty four. . . Terminal part of electronic parts

25. . . Plating

30. . . a core body to which the first solder particles are attached

40. . . container

41. . . Dispersions

114. . . Second solder particle

114a. . . Solder film

Fig. 1 is a flow chart for explaining a manufacturing procedure of a circuit board according to a first embodiment of the present invention.

Fig. 2 is a flow chart showing the steps of manufacturing the circuit board according to the first embodiment of the present invention.

Fig. 3 is a schematic view showing the step of attaching the first solder particles.

Fig. 4 is a flow chart for explaining a manufacturing procedure of a circuit board according to a second embodiment of the present invention.

Fig. 5 is a flow chart for explaining a manufacturing procedure of a circuit board according to a third embodiment of the present invention.

Fig. 6 is a flow chart for explaining a manufacturing procedure of a circuit board according to a fourth embodiment of the present invention.

Fig. 7 is a flow chart for explaining a manufacturing procedure of a circuit board according to a fifth embodiment of the present invention.

Fig. 8 is a flow chart for explaining a manufacturing procedure of a circuit board according to a sixth embodiment of the present invention.

1. . . Circuit substrate

1a. . . Above the circuit board

2. . . Terminal part

3. . . Resist layer

4. . . Terminal surface

5. . . First adhesive layer

6. . . Opening

11. . . Nuclear body

12. . . Nuclear surface

13. . . Second adhesive layer

14. . . First solder particle

Claims (18)

A method of manufacturing a circuit board, comprising: coating a first adhesive layer on a surface of a terminal portion of a circuit board to form a first adhesive layer, and attaching the core body to the first portion of the terminal portion a step of adhering a second adhesion-promoting compound to the surface of the core body to form a second adhesive layer, and attaching the first solder particles to the second adhesive layer on the surface of the core body And a step of melting the first solder particles to form a solder layer on the surface of the core body. The method of manufacturing a circuit board according to the first aspect of the invention, comprising the steps of: applying the first adhesion-imparting compound to the surface of the terminal portion to form the first adhesive layer, and transmitting the first a second adhesive layer, wherein a core body to which the first solder particles are attached to the surface and adhered to the first solder layer is adhered to the first adhesive layer, and the first solder particles are melted on the surface of the core body The step of forming the aforementioned solder layer is performed. The method of manufacturing a circuit board according to claim 1, wherein after the step of attaching the first solder particles to the second adhesive layer, the second solder particles are adhered to the first adhesive layer. When the step of forming the solder layer is performed on the surface of the terminal portion, the first solder particles and the second solder particles are simultaneously melted. The method of manufacturing a circuit board according to the first aspect of the invention, wherein the step of attaching the core body to the first adhesive layer and the step of forming the second adhesive layer have a first adhesive layer The second solder particles are adhered to the surface of the terminal portion, and when the solder layer is formed, the first solder particles and the second solder particles are simultaneously melted. The method of manufacturing a circuit board according to claim 1, wherein the step of forming the first adhesive layer has a step of attaching the second solder particles to a surface of the terminal portion, and forming the solder layer The first solder particles and the second solder particles are simultaneously melted. The method of manufacturing a circuit board according to claim 1, further comprising the step of: adhering the second solder particles to a surface of the terminal portion, and melting the second solder particles to form a surface of the terminal portion a step of forming a solder film by applying a first adhesion-promoting compound to the surface of the terminal portion through the solder film to form a first adhesive layer, and forming the solder layer to form the first solder The particles are simultaneously melted with the aforementioned solder film. The method of manufacturing a circuit board according to claim 1, further comprising the steps of: forming a solder film on the surface of the terminal portion by electroplating, and applying a first pass to the surface of the terminal portion through the solder film; The step of forming the first adhesive layer by the adhesive compound, and simultaneously forming the solder layer, the first solder particles and the solder film are simultaneously melted. The method of manufacturing a circuit board according to claim 3, wherein the second solder particles have an average particle diameter of 1 μm or more and 0.4 times or less the average particle diameter of the first solder particles. The method of manufacturing a circuit board according to claim 4, wherein the second solder particles have an average particle diameter of 1 μm or more and 0.5 times or less the average particle diameter of the core body, and are higher than the first solder particles. Small. The method of manufacturing a circuit board according to claim 9, wherein the second solder particles have an average particle diameter of 5 to 10 μm. The method of manufacturing a circuit board according to the sixth aspect of the invention, wherein the second solder particles have an average particle diameter of 1 μm or more and 1/3 or less of a diameter of the terminal portion. The method of manufacturing a circuit board according to the first aspect of the invention, wherein the circuit board having the first adhesive layer is immersed in a dispersion liquid containing the core body, and the core body is attached to the first adhesive layer. . The method of manufacturing a circuit board according to claim 2, wherein the circuit board having the first adhesive layer is immersed in a dispersion containing the core body to which the first solder particles are attached, and the first solder is attached. The core body of the particle is attached to the first adhesive layer. The method of manufacturing a circuit board according to the first aspect of the invention, wherein the circuit board to which the core body having the second adhesive layer is adhered is immersed in the dispersion liquid containing the first solder particles, and the A solder particle is attached to the surface of the core body. The method of manufacturing a circuit board according to the second aspect of the invention, wherein the core body having the second adhesive layer is immersed in a dispersion liquid containing the first solder particles, and the first solder particles are attached to the first On the second adhesive layer, the core body to which the first solder particles are attached is formed. A method of manufacturing a circuit board according to claim 1, wherein a metal ball is used as the core body. The method of manufacturing a circuit board according to claim 1, wherein the core system is made of copper. In the method of manufacturing a circuit board according to the first aspect of the invention, in the step of forming the first adhesive layer, the first adhesive layer is formed on the circuit substrate by forming an insulating layer having an opening portion through which the terminal portion is exposed. Floor.